1. Field of the Invention
The field of this invention lies within the energy and voltage control art. More particularly, it lies within the art of providing a discrete amount of energy and/or voltage to a system for optimizing its function without creating a situation wherein excessive amounts of energy are utilized. More particularly, it optimizes a lighting system, such as a bank of high intensity discharge lamps or fluorescent lamps to optimize the output of light, while at the same time eliminating substantial energy consumption.
2. The Prior Art
The prior art related to energy consumption and attendant voltage control, has generally involved a discrete switching from one voltage or energy level to another voltage or energy level. The discrete switching is such that it has been performed by relay functions, potentiometers, and other devices known in the art.
Recently, it has come to the attention of industrial and commercial users of energy, that substantial savings can be accomplished if lighting costs can be decreased. In particular, lighting costs can be decreased by means of a number of methods, including the foregoing prior art methods.
some methods have incorporated the elimination of certain lights and provided other types of lights. Others have changed the characteristics of the ballasts that have been used to light certain gaseous lights.
Oftentimes, in order to save energy with regard to lighting fixtures, solid state ballasts have been resorted to. The drawback of solid state ballasts is they are expensive and must be reinstalled, thereby increasing the costs from the standpoint of the initial installation, as well as the cost of materials.
Another means of reducing energy for lighting fixtures has been to provide for new fixtures which use lesser light. This generally requires a re-engineering and remodification of the ceiling, as well as other efforts to accommodate the new fixtures. As can be appreciated, this is an expensive and generally not acceptable means for saving energy for commercial and industrial users.
In addition to the foregoing means of saving lighting energy, certain computer managed systems have been developed. In effect, this creates a local shedding wherein energy is shed in various locations or at different times of the day, depending upon demand. As can be appreciated, it is very difficult to shed energy with regard to light requirements, inasmuch as people generally have to have a certain amount of light to function and entire banks of lights cannot be shut down in certain areas.
Certain types of low energy lamps for high efficiency have also been recommended and tried in order to provide for increased efficiency with regard to lighting functions. The low energy lamps are such that they can oftentimes perform the job but are expensive. Furthermore, the expensive oftentimes is increased by additional expenses in having to reinstall low energy lamps that are substantially more expensive than regular lamps.
All of the foregoing methods of trying to conserve lighting energy have been deemed somewhat effective, but very expensive. Accordingly, this invention serves to overcome the deficiencies of the prior art and is very cost effective.
Recently, an attempt has been made to change the voltage levels with regard to incandescent discharge lamps and fluorescent lamps that have been previously installed. The effort has generally involved the changing of power delivered to the lamps by means of a switching network. Also, there has been an effort to use relay contacts, discrete transformer taps, and pre-selected timing.
The switching network is such that it switches between certain transformer taps to provide various levels of voltage to a bank of lights. The switching function can be provided by a number of discrete switches, depending upon the amount of change or different levels of voltage that are required by the lamps, as well as the number of lamps, or lamp circuits, to be controlled.
This has been exemplified by U.S. Pat. No. 4,189,664 issued to Richard L. Hirschfeld. The drawback of this kind of a system is that it radically changes the level of voltage from a higher level to a lower level, at which the lamps will operate. However, in making the change, it oftentimes extinguishes the fluorescent lamps and is not functional with respect to high intensity discharge lamps (HID lamps).
The foregoing extinguishing of lights is particularly prevalent with regard to high intensity discharge (HID) lamps, such as high pressure sodium, low pressure sodium, metal halide, and mercury vapor lamps. These types of lamps, when radically changed in voltage level, are extinguished. As a consequence, such a system has not worked at all on HID lamps.
To the contrary, this particular invention and controller works well to reduce high intensity discharge lamps from a higher level to a lower level of voltage for attendant energy savings. The invention is uniquely capable of metering the rate of change to accommodate arc tube temperature/pressure changes.
In addition to the foregoing features, the invention is such that it does not alter the wave form of the applied voltage. It effectively provides a means for starting the gaseous discharge lamps at a full rated voltage, or for that matter, other electrical equipment. This permits the lamps or electrical equipment to be stabilized and reach a normal operational equilibrium.
After normal operating equilibrium has been reached, the invention, as distinguished from the prior art, smoothly reduces the voltage at a prescribed rate of change compatible with change in arc tube temperatures and pressures internal to the lamp and maintains the voltage at a substantially constant level, even when the input voltage level changes.
Also, as distinguished from the prior art, the invention provides a means for reducing the output voltage over a predetermined time span from a full rated voltage to a selected lower voltage which is still sufficient to operate the lamps and provide an energy saving, while at the same time providing sufficient lighting energy for one to function in a normal capacity.
The invention can be installed in a distribution feeder line between the electrical source and a distribution panel, which further distinguishes if from the prior art, thereby avoiding the cost of retrofit as to new fixtures, solid state ballasts, computer managed local shedding, or low energy lamps, or, the cost for a multiplicity of switching relays required to switch a multiplicity of lamps or lamp circuits to various taps on a fixed ratio or fixed ratio autotransformer.
The invention allows for additional banks of lights or other devices to be put on the line by automatically resetting the voltage level to a full rated voltage. It also provides for the ability to interface with other sensors and control devices.
Finally, the invention overcomes the deficiencies of the prior art by allowing a set point output voltage level to be located at any particular value with respect to related voltage while at the same time sensing and compensating for additional electrical loads when added to the line controlled by this device. Further, the device adjusts for variances of the input voltage such that a pre-established set point output voltage level is maintained.
As a consequence, this invention is a substantial step over the prior art and should be read broadly in light of the following specification and claims attendant therewith.